The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Motorized vehicles traditionally include a power supply (e.g. an internal combustion engine, an electric motor and/or a combination thereof) that produces a drive torque. A transmission receives the drive torque and employs various gear ratios to modify the input drive torque to obtain a desired output torque for the wheels.
One or more control modules regulate operation of the power supply and transmission to achieve this desired output torque. For example, an engine control module may regulate a throttle controlling air entering the internal combustion engine, while a transmission control module may regulate the various gear ratios transmitting the output drive torque. Additionally, the functions of the engine and transmission control modules may be incorporated into a single powertrain control module. The control module(s) may receive direction from a driver interface device, such as an accelerator pedal. As the accelerator pedal position is changed, the control module(s) select operating conditions to achieve a specific gear ratio corresponding to the requisite output torque. The specific gear ratio is obtained from a lookup table of current throttle versus vehicle speed.
In operation, a driver may require a rapid switch between specific gear ratios. This normally occurs when the transmission downshifts due to driver requested rapid acceleration (e.g. when passing another vehicle). Switching between gear ratios can occur as a stacked single-step multiple downshift (e.g. a first shift from 6-5 followed by a second shift from 5-4), a jump downshift (e.g. 6-4), or a skip downshift (e.g. 6-3). In the stacked single-step multiple downshift, an inability to abort an on-going first downshift causes a delay in initiating the second downshift. The driver may perceive this as poor downshift response or an undesirable second shift event. Further, since the downshift types are commonly determined relative to the pedal position as a function of time, rather than using an accelerator pedal position rate of change and/or an accelerator pedal velocity rate of change, the driver may also perceive inconsistent downshift types under low, medium, and high tip-in maneuvers (e.g. depression of the accelerator pedal).